Officials say 13 people were taken to hospital — two of them in critical condition — after carbon monoxide was detected when paramedics responded to a call on Wednesday at an office building in Vancouver.
Emergency Health Services says on Twitter that paramedics were responding to a call about a patient who had collapsed.
It says paramedics wear carbon monoxide monitors and when they arrived the devices immediately detected the gas, which is colourless and odorless.
The agency says a total of 13 patients were treated for poisoning and transported to hospital.
No other details were released by Emergency Health Services but FortisBC spokesman Scott Neufeld says the energy company was called to an office building at about 10 a.m.
He says the company’s technician detected a problem with the boiler.
Carbon monoxide is produced when fuel is burned and can cause health problems or death when inhaled.